Studies towards a disposable screen-printed amperometric biosensor for progesterone.
A screen-printed carbon electrode (SPCE) has been investigated as the base transducer for a disposable amperometric progesterone biosensor. The biorecognition element was a monoclonal sheep anti-progesterone antibody (mAb). This was immobilized onto the transducer by interaction with a layer of rabbit IgG which had been previously coated onto the SPCE; optimum conditions for these loadings were deduced experimentally. The device was employed in a competitive assay using alkaline phosphatase-labelled progester-one. Three possible substrates for the enzyme were considered, namely, phenyl phosphate, phenolphthalein phosphate and 4-aminophenol phosphate. Cyclic voltammetry and amperometry were carried out on the corresponding aromatic phenols and phenol itself was found to give the best electrochemical characteristics; consequently, phenyl phosphate was employed as the substrate. Chronoamperometry was used to measure the phenol produced by the reaction of bound enzyme-labelled progesterone and substrate. The chronoamperometric response was dependent on unlabelled progesterone over at least three orders of magnitude with a detection limit of about 1 x 10(-9) mol/dm3. This suggests that the device may have applications for the analysis of biological fluids.
Hart
J P
JP
Faculty of Applied Sciences, University of the West of England, Bristol, UK.
Pemberton
R M
RM
Luxton
R
R
Wedge
R
R
D000627:Aminophenols / Q000032:analysis; D001667:Binding, Competitive; D015374:Biosensing Techniques; D002138:Calibration; D002244:Carbon; D004209:Disposable Equipment; D004563:Electrochemistry / Q000295:instrumentation*; D019800:Phenol / Q000032:analysis; D020113:Phenolphthalein; D010635:Phenolphthaleins / Q000032:analysis; D011374:Progesterone / Q000032:analysis*
D000627:Aminophenols; D010635:Phenolphthaleins; D019800:Phenol; D011374:Progesterone; D020113:Phenolphthalein; D002244:Carbon; C026729:4-aminophenol